The present invention relates to reciprocating saws and more specifically to a keyless blade clamp for quickly and easily replacing and securing a saw blade to a spindle of a reciprocating saw.
Hand held reciprocating tools, such as electric reciprocating saws, include removable blades, which permits the use of different cutting edges as may be necessary for cutting different materials and for the replacement of worn or damaged blades. This requires a blade mounting system that allows rapid blade replacement while accurately and firmly coupling the blade to the tool. Typically, blade mounting systems require a tool, such as an allen wrench or a special key, in order to replace and secure the blade. This is a slow and often difficult process.
Recently, blade clamps have been developed that do not require a tool. These clamps are commonly called keyless blade clamps. While many existing keyless blade clamps are a vast improvement over standard blade clamps that require tools, there is still a need for keyless blade clamps that are easy to manufacture, simple to use, and long-lasting.
There are several aspects of the present invention, each of which is summarized below.
In one aspect, the present invention provides a reciprocating saw comprising a reciprocatable spindle having an end adapted to receive a saw blade, and a blade clamp mechanism connected to the spindle and adapted to attach the saw blade to the spindle. The blade clamp mechanism includes an actuating member mounted on the end of the spindle, a locking member operatively associated with the actuating member, a biasing member (e.g., a torsional coil spring) interconnected with the actuating member for biasing the actuating member toward an engaged position, and a cover enclosing a substantial portion of the biasing member. By virtue of the use of a cover, the biasing member is at least partially protected from obstruction, contamination or tampering, which may interfere with the operation of the spring.
In another aspect, the blade clamp mechanism includes an actuating member movably mounted on the end of the spindle, a locking member operatively associated with the actuating member and moveable relative to the spindle, a biasing member interconnected with the actuating member for biasing the actuating member toward an engaged position, and a housing mounted to the actuating member. Preferably, the housing comprises a substantially thermally insulative material (e.g., a plastic or polymeric material). The housing can further include a plurality of arcuate recesses on an exterior surface of the housing. By virtue of the provision of a housing mounted to the actuating member, heat transfer from the blade to the user is reduced. In addition, the arcuate recesses facilitate engagement of the housing by the user.
The present invention also provides a method of assembling a blade clamp mechanism for attaching a saw blade to a spindle of a reciprocating saw. The method comprises the acts of positioning an actuating member onto the spindle, aligning (e.g., rotating) the actuating member relative to the spindle such that an opening in the spindle is substantially aligned with an opening in the actuating member, inserting a locking member through the opening in the actuating member and through the opening in the spindle, and moving the tab member into the opening in the actuating member. In one embodiment, the method further includes the act of interconnecting the actuating member to a biasing member. Preferably, the method further includes the act of positioning a cover over a substantial portion of the biasing member.
In another aspect, the present invention provides a reciprocatable spindle having an end adapted to receive a saw blade, and a blade clamp mechanism connected to the spindle and adapted to attach the saw blade to the spindle. The blade clamp mechanism includes an actuating member movably mounted on the spindle, a locking member operatively associated with the actuating member and moveable relative to the spindle, and an ejecting member interconnected with the spindle and capable of engaging the saw blade such that the saw blade is urged away from the end of the spindle. By virtue of this feature, removal of the saw blade from the spindle is facilitated. This is particularly helpful if the tang of the saw blade is broken off in the spindle.
In one embodiment, the saw further includes a biasing member (e.g., a spring) interconnected with the actuating member for biasing the actuating member toward an engaged position. Preferably, the ejecting member comprises a portion of the biasing member. For example, the ejecting member can be positioned in a recess (e.g., a slot) and can engage the saw blade.